Questions and Answers
What are dendrites?
Dendrites receive nerve impulses from other neurons or sensory receptors and transmit the nerve impulses towards the cell body/soma of the neuron.
What is an axon?
An axon is an extension from the cell body that transmits the nerve impulses away from the cell body towards the synaptic bulbs.
Describe the structure of sensory neurons.
Sensory neurons have long dendrites and short axons.
What is the function of sensory neurons?
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What is the structure of relay neurons?
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What is the function of relay neurons?
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Describe the structure of motor neurons.
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What is the function of motor neurons?
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What does the strength of the muscle contraction depend on?
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What causes muscle relaxation?
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Study Notes
Structure of Neurons
- Dendrites: Receive nerve impulses from other neurons or sensory receptors and transmit them towards the neuron's cell body.
- Axon: An extension from the cell body that transmits nerve impulses away from the cell body toward synaptic bulbs.
- Sensory Neurons: Characterized by long dendrites and short axons, allowing them to quickly relay information from sensory receptors.
- Relay Neurons: Have short dendrites and short axons, located in the brain and spinal cord, facilitating communication between sensory and motor neurons.
- Motor Neurons: Feature short dendrites and long axons. They originate in the central nervous system (CNS) and extend into the peripheral nervous system (PNS) to stimulate muscles or glands.
Functions of Neurons
- Sensory Neurons: Convert sensory information (e.g., pain, heat, visual input) into nerve impulses, transmitting them to the spinal cord and brain. In reflex actions, they communicate directly with the spinal cord to expedite responses.
- Relay Neurons: Act as intermediaries between sensory and motor neurons, found exclusively within the brain and spinal cord.
- Motor Neurons: Carry impulses from the CNS to effectors such as muscles and glands. They control muscle contractions by releasing neurotransmitters at synapses, which bind to muscle receptors, generating action potentials that lead to contraction.
Muscle Contraction and Relaxation
- Strength of Contraction: Dependent on the firing rate of action potentials by neurons.
- Muscle Relaxation: Occurs due to the inhibition of motor neurons, preventing muscle contractions.
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Description
Test your understanding of sensory, relay, and motor neurons with our comprehensive flashcards. This quiz covers essential definitions and functions of key neuron components like dendrites and axons, helping you solidify your knowledge of neuroscience.